Casing cutter



Sept. 27, 1 927,

G. D. FAWCETT CASING ct'm'En Filed 001:. 5, 1925 's Sheets-Sheet 1 Sept. 27,1927,

6. D. FYAWYCETT CASING CUTTER 1 m "I 2 Q m I;

5 [I a x 1 5 7 -m nmi vv v 5 \a j I WI W 2 W 4 v 4 Patented Sept. 27, 1927.

UNITED STATES PATENT OFFICE.

GERALD D. FAWCETT, 0F WEITTIER, CALIFORNIA.

I CASING CUTTER.

Application filed October 5, 1925. Serial No. 60,669.

This invention relates to improvements in devices for cut-ting 03 well casing and other well pipe which is located in a well.

An object of the invention is to provide an improved casin cutter which may be used and operated y means of a cable, as distinguished from tools which are used and operated by rotary drill pipe.

Another object of the invention is to provide a, casing cutter which may be lowered into a well by means of a cable, set in posit-ion in the casing or other well pipe by the cable and operated upon reciprocation of the cable to out off the pipe or casing. I

With the foregoing and other objects in view which will be made manifest in the following detained description and specifically pointed out in the appended claims, reference is had to the accompanying drawings for an illustrative embodimentof the invention, wherein:

Figure 1 is a vertical section through a casing, and through the improved casing cutter therein, illustrating the position of the tool upon being lowered into the well,

Fig. 2 is a view similar to Fig. 1 illustrating the position which the tool assumes preparatory to becoming set,

Fi 3 is a view similar to Fig. 1 illustrating t e tool in set position,

Fig. 4 is a view slmilar to Fig. 1 illustrating the position of the tool after the cutters have been completely expanded and the casin out,

ig. 5 is a detail view illustrating the upper portion of the tool,

Fig. 6 is a detail view showing the lower portion of the tool,

Fig. 7 is a horizontal section taken sub-, stantially on the line 7-7 of Fig. 5,

Fi 8 is a horizontal section taken substantially on the line 8-8 of Fig. 5,

Fig. 9 is an enlarged vertical section i1- lustrating the latch in its retracted position,

Fig. 10 is a horizontal section taken on the .line 10-10 of Fig. 6,

Fi 11 is a horizontal section taken on the hue 11--11 on Fig. 6 in the direction indicated, and

Fig. 12 is a line 1212 of Fig. 6.

Referring to the accompanying drawings wherein similarreference characters desig nate similar parts throughout,the im roved casing cutter consists of a barrel pre erably formed of two sections of pipe, seamless tubhorizontal section taken on the Fig. 10)

ing or the like,v one of which is indicated at 10 and the other being indicated at 11. The upper section 11 is smaller in diameter than. the lower section 10 and is threaded into its upper end. The upper end of the upper sec-" tion 11 is enlarged, as at 12, and presents a conical or tapered exterior surface. About the upper section 11 there are slidable two rings or hands 13 and 14 which are connected by means of strips 15 and friction springs 16. These friction springs are so arranged as to engage upon the interior surface of the well casing C which is to be cut. tending upwardly from the upper ring or band 14 are links 17 which are connected to slips 18 fitting about the enlarged portion 12. These slips are provided with horizontal and vertical teeth 30 and 31' respectively and when expanded are adapted to engage upon the interior of the wellcasing C. A groove 19 is formed upon the exterior surface of the upper section 11 and a leaf spring 20 has its upper end rigidly secured within this groove, as indicated by the rivets 21. This leaf spring is so arranged that it normally occupies a position within the groove 19, as indicated m Fig. 9, but it may be sprung outwardly from the. groove, as shown in Fig. 5, and has a shoulder 22 formed near its lower end which is engageable upon the lower rin or band 13, so as to prevent upward sliding of the bands 13 and 14 while the tool .is being lowered into the well.

A reciprocating member 23 is reciprocable within the barrel and'has its upper end enlarged, providing a head 24 and a pin 25, to which one or more sections of dril stems may be connected .to provide suflicient weight to operate the cutter and to .which sections the operating cable may be connected. Below the lower end of the upper section 11 of the barrel the reciprocating member 23 is enlarged providing a head 26 which fits rather closely within Slots 27 are formed in the opposite sides of the lower section 10 and receive the ends of a pin 28 passing through the head preventing rotation of the reci member 23-within the barrel.

rocating slow the the lower section 10.

26, thus head 26 on the reciprocating member there are formed one or more helical grooves 29 which receive keys 20 upon a rinpiwtil arranged about the reclprocating mem The lower end of the lower section 10 has threaded into it a sub 32 on which rests a bearing 33 shown as consisting of two races ring 31 and the collar 34. The ring 31 is;

- i mamtainedwithinthe recess 35in any suitable. manner, such as by a disc 39 held in place within the lower section 10 of the barrel as by one or morescrews 40.

A rotating sub 41 fits between the lower end of the reciprocating member 23 and the.

sub 32, and has its-upper end threadedly connected to the collar 34. The lower end of the rotating sub 41 has a hollow stem 42 threaded to it, which stem carries on its lower end the cutter body 43. A bore 44 extends longitudinally or vertically through the cutter body and radial passages 45 communicate with it. In the passages 45 there are ar anged. cutter blocks 46 carrying inwardl extending fingers or ribs 47 and rotary isc cutters 48. The cutter blocks 46 are slidable in the passages and may be moved outwardly therethrough, thus expanding the cutters.- They are urged into their innermost or retracted positions by means of springs 49, which are compressed between the outer faces of the. blocks and lugs 50. The hollow stem 42 is externally threaded to receive a collar 51 carrying friction springs 52 en ageable u on the interior,

surface of the we casing In the op 0- site sides of the stem there are formed s jots 53 through which extend the ends of a crossbar 54 carrying rollers 55 which engage upon the bottom surface of the collar 51. A

rod 56 connects the center of the crossbar 5.4

to the to of a tapered mandrel 57 movable within t e hollow stem 42 and within the bore 44 in the cutter body 43. The ta ered mandrel 57 en ages the fingers or ri s 47 on-the cutterbfocks 46, and when the mandrel .moves downwardly within the cutter body, it will force the cutter blocks 46 outwardly through the passages 45 against the action of the springs 49and thus expand the cutters;

Theoperation of the casing cutter is as 7 follows: The tool is lowered into the well withinthe casing C in a position as shown in'Fig. 1, in which the slips'18 are at thebottom of the enlarged portlon 12 on the up,

per sections 11 and the lower band 13 1s eld against upward sliding by the leaf spring'orlatch 20 having its shoulder .22 restin thereon. {On lowering the device into e well casing both sets of friction springs 16 and 52 engage the inside of the casing while moving downwardly. The weight of the drill stems secured to the pin 25 is sufficient to cause the complete tool to slide downwardly within the casing, and

when it has reached the proper location, the

11.- By continuing the upward movement of the reciprocatingmember 23, the barrel will be caused to slide upwardly a short distance within the bands Band 14 which are frictionally held stationary This movement allows the end of the leaf spring orlatch 20 to disengage from the band 13, and the spring will snap into the-groove 19 and 0ccupy its .retracted position, as shown in Fig.

9. In this manner the latch is disengaged.

fromthe band 13 and the barrel is capable of upright sliding downwardly within both of the bands. The cable is then let down, lowering the reciprocating member 23 and the barrel until the slips 18 are expanded by the enlarged portion 12, causing the slips.

to engage upon the inside of the casing.

Because of the vertical as well ashorizontal.

teeth upon the slips, it will be readily appreciated that the barrel will not be able to move downwardly or to be rotated within the casing after the slips have become set, and in this manner the barrel is held stationary within the casing preparatory to the cutting. After the barrel has become set, the reciprocating member 23 is vertically 'reciprocated within it by means of the cable,

, and in the other direction uponits up stroke.

During'the upstroke the ring 31 is rotated in that direction in which the pawl 37 merely slips over the teeth 36. During the down stroke, however, the ring 31 rotates in the opposite direction and the pawl 37 engages one of the teeth, causing the collar 34, the rotating sub 41 and the stem 42 together with the cutter body 43 to rotate with it.

The rotation of the collar 51, however, is prevented by means of the friction springs 52, so that whilethestem 42 is being rotated,

the collar 51 is gradually screwed down upon the 'stem. The downward movement of the collar 51 against the roller 55 causes the tapered mandrel 57 to move downwardly between the cutter blocks 46, thus gradually expand ng the cutters while the cutter body 43 is being rotated. Because of the con- I, struction of the subs'32 and 41 and the tapered retracted collar 34, it will be readily appreciated that vertical movement of the stem 42- relatively to the barrel is prevented, and as the barrel is held stationary within the casing by the slips, thevdiscs 48 will always be cutting 1n the same groove. The reciprocation of the reciprocating member 23 is continued until the cutter blocks 46 have been completely expanded and the casing cut. When the blocks have been completely expanded, the fingers or ribs 47 pass over the to of" the mandrel 57 and are returne to their v position about the rod 56 by the coil springs 49, as shown in Fig. 4. The tool can then be withdrawn from thecasing by pulling upwardly upon the cable, causing the head 26 to strike the lower end of the section 11 and-unseat the slips 18. In this manner the head 26 and the upper, section 11 provide atype of jar for loosening the slips from the casing. In, originally setting the tool after the slips have engaged the casing, the reciprocating member "may be lowered several times causing the head 24 to engage the top of the barrel and act as a hammer in firmly seating the slips upon the casing.

Fro m hbove it W111 be appreciated that an improved casing cutter {is provided, which can be lowered into a well by means-of a cable and then withdrawn from thewell by the cable.

ta drill i j an outfit. P 8

It will be readily appreciated that the stem42 can be rotated in any'zone of a number of various manners,either employing a reciprocating cable, or, if desired,

this stem canbe rotated by meanyof a re.-

if the tool onsequently, the stem 42 and parts associated with it constitute a 'sub- 5' combination. of the complete tool which can It will be understood that various changes ma be made in the detail of construction i wit out departing from the spiritor scope of. 'he invention as defined by the appended L 1, A casing cutter comprising a hollow stem, a cutter body secured thereto, cutters "-1 5- ciaaiau .slidable upon body, mm

drel movablfwiithin said body'for moving the cutters outwardly therethroug'h, a collar" threaded onto-the-stem, means carried by; the collar engageable upon the interior of the casing =fo'r. preventing (its rotation, means rotating 'said' and means' formin 'a'c'onnection between the mandrel and "sai collar whereby upon rotation of said stem the collar will move relatively thereto, movcutters during rotation.

'stem, friction springs interior of the set in position and operated by'jthe is used upon such mg, the mandrel and thusexpanding the adapted to 2. A casing cutter comprising a hollow stem, a cutter body securedthereto, cutter blocks slidable within said cutter body, disc cutters mounted on said cutter blocks, a

tapered mandrel movable within said body engageable uponsaid cutter blocks .for expanding them, a collar threaded onto the engageable upon the casing carried by said collar for preventing rotation of the collar, means for rotating said stem so as to cause said collar to move relatively thereto, and means formin a connection between the mandrel and said collar whereby the mandrel may be caused to expand the cutters causing the cutters to be simultaneously rotated and expanded upon rotation of the stem.

3. A casing cutter comprising a hollow stem, a cutter body secured thereto, cutters movable outwardly from said cutter body, a tapered mandrel disposed within the body for forcing the cutters outwardly, said mandrel carrying arms which slidably extend slots in the stem, a collar threaded onto the stem, means carried by the collar engageable upon the casing for holding the collar against rotation, and means for rotating the stem causing the collar to en ge said arms and thus cause the mandre to body is rotating with the stem.

4. A casing cutter comprising a hollow stem, a cutter body secured thereto, cutter u on the cutter-blocks,.-a tapered mandrel d1sposed.within the cutter body, arms car- ,blocks slidable in the body, cutters rotatable ried by the mandrel'extending through slots I in the stem, acollar threaded onto the stem, friction springs carried .by the collarengageable upon the interior of the casing-for hold-in the collar against rotation, rollers carrie by saidarms bearing against the collar, and means for rotating the stem whereby the cutter body may be rotatedand the collar may be moved relatively to the stem, causing the mandrel {to force the cut ter blocks outwardly. 1

5. A casing cutter comprising a barrel having a upon the the tapered upper end, friction springs slidable upon the-barrel and connected to the slips, a spring, latch for holding the friction tapered upped end, slips slidable sprin s against upward movement on lowering' t e device into a well hole, a recipr0cat-. 111g member having a head adapted tolift *the' barrel anld cause the latch to release the spr ngs .sal reciprocatin r member he" '7 he l d against-rotation in mg be ng helical grooves formed upon said re ciproca ting member, a hollow. stem rotatably' mounted u on' the, barrel-vat the bottom thereof an extending downwardly therefrom, a rm disposed within the barrel rotated by the reciprocating barrel adapted to be expanded by 6 barrel, there member upon its reciprocation, means providing a ratchet and pawl connection be tween the ring and said stem, a cutter body rigidly secured to said stem, cutters movably mounted thereon, a Wedge for expanding the cutters, a collar threaded onto the stem, means connecting the collar to said wedge, said collar being engageable upon the casing to hold it against rotation,- and means produced, thus causing rotation of the cutterbody and causing the collar to move relatively thereto to cause the Wedge to force.

the cutters outwardly.

In testimony whereof I have signed my name to this specification.

GERALD D. FAWCETT. 

